Stock Quotes in this Article: AZPN, DIOD, AMBA

MADISON, Wis. (Stockpickr) -- Professional traders running mutual funds and hedge funds don't just look at a stock's price moves; they also track big changes in volume activity. Often when above-average volume moves into an equity, it precedes a large spike in volatility.

Major moves in volume can signal unusual activity, such as insider buying or selling -- or buying or selling by "superinvestors."

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Unusual volume can also be a major signal that hedge funds and momentum traders are piling into a stock ahead of a catalyst. These types of traders like to get in well before a large spike, so it's always a smart move to monitor unusual volume. That said, remember to combine trend and price action with unusual volume. Put them all together to help you decipher the next big trend for any stock.

With that in mind, let's take a look at several stocks rising on unusual volume today.

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Diodes

Diodes (DIOD) is a manufacturer and supplier of application specific standard products within the broad discrete, logic and analog semiconductor markets, serving the consumer electronics, computing, communications, industrial and automotive markets. This stock is trading up 8.2% at $22.30 in recent trading.

Today's Volume: 369,000

Average Volume: 231,446

Volume % Change: 157%

Shares of DIOD are soaring higher here after Robert W. Baird upgraded the stock to outperform from neutral and raised its price target to $29 from $20.

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From a technical perspective, DIOD is gapping sharply higher here and entering breakout territory above some near-term overhead resistance levels at $21.64 to $21.66 with above-average volume. This move has pushed shares of DIOD into new 52-week high territory, which is bullish technical price action.

Traders should now look for long-biased trades in DIOD as long as it's trending above those key near-term breakout levels, and then once it sustains a move or close above its 52-week high at $22.46 with volume that hits near or above 231,446 shares. If DIOD can maintain this move, then this stock will set up to re-test or possibly take out its next major overhead resistance levels at $25 to $27.50.

Aspen Technology

Aspen Technology (AZPN) supplies process optimization software that allows manufacturers to implement best practices for optimizing their engineering, manufacturing and supply chains. This stock is trading up 3.5% at $28.54 in recent trading.

Today's Volume: 1.17 million

Average Volume: 528,256

Volume % Change: 225%

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From a technical perspective, AZPN is jumping higher here right above its 200-day moving average at $27.21 with heavy upside volume. This stock recently dropped sharply from $32.67 to around $26.50 with heavy downside volume. Shares of AZPN are now rebounding off its recent low and quickly moving within range of triggering a near-term breakout trade. That trade will hit if AZPN manages to clear some near-term overhead resistance at around $29.55 with high volume.

Traders should now look for long-biased trades in AZPN as long as it's trending above its 200-day at $27.21 and then once it sustains a move or close above $29.55 with volume that hits near or above 528,256 shares. If that breakout triggers soon, then AZPN will set up to re-test or possibly take out its next major overhead resistance level at its 50-day moving average of $30.76.

Ambarella

Ambarella (AMBA) is a developer of semiconductor processing solutions for video that enable high-definition video capture, sharing and display. This stock is trading up 5.6% at $14.75 in recent trading

Today's Volume: 1.12 million

Average Volume: 383,224

Volume % Change: 317%

From a technical perspective, AMBA is ripping higher here right above its 50-day moving average of $13.11 with heavy upside volume. This move has started to push shares of AMBA into breakout territory, since the stock is flirting with some near-term overhead resistance levels at $14.50 to $15. This move is also quickly pushing shares of AMBA within range of triggering another major breakout trade. That trade will hit if AMBA manages to take out its all-time high of $16 with high volume.

Traders should now look for long-biased trades in AMBA as long as it's trending above $14.50 or above today's low of $13.99, and then once it sustains a move or close above $16 with volume that hits near or above 383,224 shares. If that breakout triggers soon, then AMBA will set up to enter new all-time high territory above $16, which is bullish technical price action. Some possible upside targets off that move are $18 to $20.

To see more stocks rising on unusual volume, check out the Stocks Rising On Unusual Volume portfolio on Stockpickr.

-- Written by Roberto Pedone in Madison, Wis.

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At the time of publication, author had no positions in stocks mentioned.

Roberto Pedone, based out of Madison, Wis., is an independent trader who focuses on technical analysis for small- and large-cap stocks, options, futures, commodities and currencies. Roberto studied international business at the Milwaukee School of Engineering, and he spent a year overseas studying business in Lubeck, Germany. His work has appeared on financial outlets including CNBC.com and Forbes.com. You can follow Pedone on Twitter at www.twitter.com/zerosum24 or @zerosum24.